1. Field of Invention
This invention relates to the treatment of ocular wounds. Ocular wounds which may be treated according to the present invention include, but are not limited to: persistent corneal defects; incisions for cataract extractions; corneal transplants; laser sculpturing of the cornea (including excimer lasers); incisions for vitreal or retinal surgery; incisions for implanting intraocular or intrastromal lenses; and scratches, burns or abrasions. For purposes of the present specification, ocular wounds such as those enumerated above which may be treated according to the present invention shall hereinafter collectively be referred to as "ocular wounds."
2. Description of Related Art
Growth factors are a family of low molecular weight proteins which have recently been shown to possess the ability to stimulate both the repair and maturation of tissues. Different growth factors act upon different types of tissue and in differing degrees. Examples of growth factors include epidermal growth factor (EGF), fibroblast growth factor (FGF), insulin-like growth factor (IGF), and platelet derived growth factor (PDGF).
A number of growth factors have had application in wound healing. A general discussion of growth factors useful in dermal wound healing may be found in an article by George A. Ksander in Annual Reports in Medicinal Chemistry, 24:223-232 (1989) and a discussion on the effects of growth factors on corneal tissue may be found in an article by D. Gospodarowicz and L. Giguere in Chapter. 3 of "Cell Biology of the Eye" (ed. David S. McDevitt), New York: Academic Press, 1982.
EGF has been the growth factor most predominantly used in healing abraided eyes. In general, EGF given four times a day (QID) over a period of days increases the rate of healing. To be most effective, EGF is dosed QID until the wound is completely healed, usually 3-4 days. Other types of growth factors, such as FGF and IGF, but not PDGF, have also been utilized in the same or similar dosing regime.
PDGF has primarily been studied in the context of dermal wound healing and has demonstrated an enhancement in collagen synthesis, as well as an increase of leukocytes in the wound area; however, an even greater activity in the area of a wound site has been demonstrated using combinations of PDGF+IGF and PDGF+EGF (Lynch, S. E. et al., Proc. Nat'l Acad. Sci., 84:7696-7700 (1987)). These types of experiments have utilized dosing regimes which emphasize'multiple applications over a period of weeks and/or the extended presence of a factor at the wound site. PDGF has not been used in connection with ocular wounds, except by Nakada, et al., Invest. Ophthal. Vis. Sci., 31(4):54 (1990), in a multiple dosing format.